Transfusion Transmitted Injuries Surveillance System (TTISS) has been monitoring adverse reactions related to the transfusion of blood, blood components, and blood products (plasma derivatives) since 2001 in Canada. As of 2007, all provinces and the Northwest and Yukon territories participate in the TTISS. The participation rate of hospitals providing transfusion services in each of these provinces and territories (P/Ts) increased gradually over time: by 2010, it was between 80% and 100% in 11 P/Ts. Only one province had a participation rate of less than 50%. The TTISS coverage is also measured by the volume of blood components (red blood cells, granulocytes, platelets, plasma and cryoprecipitates) transfused annually and, approximately 1.5 million transfusions were given in Canada each year from 2006 to 2012. Approximately 80% of these transfusions were monitored by the TTISS network.
In addition to the overall counts and proportions of adverse reactions from transfusion of blood components and blood products (plasma derivatives), this report also provides the overall and annual risks of individual adverse reactions resulting from the transfusion of blood components for the 2006-2012 period. These statistics could not be calculated for blood products because of the lack of appropriate corresponding denominator data. Minor allergic reactions as well as febrile non-hemolytic reactions were excluded as a result of inconsistent reporting of adverse transfusion reactions over the years.
A total of 3,957 cases of transfusion-related adverse reactions were reported to the TTISS from 2006 to 2012: from 461 in 2006 to 769 in 2012, corresponding to an overall seven-year increase of 67%. The surveillance protocol requires participants to send comprehensive reports on the transfusion reactions such as transfusion-associated circulatory overload (TACO), severe allergic anaphylactic reaction (include anaphylactic shocks), hypotensive reaction, acute and delayed hemolytic reaction, transfusion-related acute lung injury (TRALI), transfusion-associated dyspnea (TAD), IVIG headache, aseptic meningitis, bacterial/viral infections, and unusual reactions of clinical significance. Each reported adverse reaction is categorized not only by its severity level (which is measured by the level of medical care/intervention required for a patient as a result of developing the reaction), but also by their resulting outcome which assesses whether the patient sustained any physiological and/or physical consequence (damage/impairment of a body function) following the development of the reaction. The outcome varies from minor to major/long-term sequelae including death.